Allies are confident that threats of a grassroots leadership challenge will fail to materialise, but admit he faces a daunting task in rebuilding party morale.

The Liberal Democrats endured a particularly torrid night in the urban north of England, where left-leaning voters deserted the party in revenge for going into government with the Tories.

They lost all 10 seats they were defending in Manchester, 10 out of 12 in Hull, 10 out of 16 in Newcastle upon Tyne and nine out of 15 in Sheffield, where Mr Clegg is an MP.

In Liverpool, where the party lost 11 of 13 seats, its humiliation was heightened by the defeat of the former council leader, Mike Storey, at the hands of an 18-year-old Labour candidate.

The party lost an astonishing 23 seats to Labour in Chesterfield and six in Birmingham, which it runs in coalition with the Tories. The party's performance in the Scottish parliamentary elections was equally dismal: they managed to come first only in the island seats of Orkney and Shetland.

As councillors represent the backbone of Liberal Democrat activists, the scale of the defeat is a savage blow to the party machine.

Gary Long, whose six-strong group on Nottingham City Council all lost its seats, demanded Mr Clegg's resignation. "Our chance of recovery will be better with a new leader," he said.

Oust

There was little sign of a co-ordinated attempt to oust Mr Clegg. But he will face intense pressure from MPs and activists to spell out more clearly the party's differences with the Tories and to demonstrate where it is having an impact on coalition policy.